Four cylinder two-stroke opposing piston internal combustion engine



Dec. 26, 1967 ALBRECHT-WOLFGANG MANTZEL ,3 7 FOUR CYLINDER "TWO-STROKEOPPOSING PISTON INTERNAL COMBUSTION ENGINE Filed Oct. 31, 1966 2Sheets-Sheet 1 Fig. 2

' INVENTOR A. W. MANTZEL ATTORNEY 1967 ALBRECHT-WOLFGANG MANTZEL3,359,957

FOUR CYLINDER TWO-STROKE OPPOSING PISTON INTERNAL COMBUSTION ENGINEFiled Oct. 31, 1966 2 Sheets-Sheet 2 INVENTOR Ar 1. MANTZEL BY WZWMATTORNEY United States Patent FOUR CYLINDER TWO-STROKE OPPOSING PISTONINTERNAL COMBUSTION ENGINE Albrecht-Wolfgang Mantzel, Ingolstadt,Samhoferweg 21, Germany Filed Oct. 31, 1966, Ser. No. 590,623

Claims priority, application Germany, Apr. 15, 1966,

P 39,206 Claims. (Cl. 123-53) ABSTRACT OF THE DISCLOSURE A fourcylinder, two-stroke opposing piston, internal combustion engine withfour symmetrically arranged crankshafts on each crankshaft of which twoof the pistons act. The cylinders containing adjacent, opposed pistonsmay be formed at an angle relative to one another.

The invention concerns a four cylinder two-stroke opposing pistoninternal combustion engine having four symmetrically arrangedcrankshafts, on which two pistons act, the cylinders of which arearranged at an angle relative to one another. Such engines are alreadyknown and have the exclusive shape of a square, since the centres of thecrankshafts are arranged in a square relative to one another.

Other opposing pistons two-stroke internal combustion engines are shownin diiferent embodiments in the form of series engines. They areconstructed either with two crankshafts at the ends of the cylinders orthey are made with a common crankshaft and push-rods and opposingpistons.

In two-stroke opposing piston engines it is moreover known to produce anasymmetric control by advancing the piston controlling the exhaust port.

The object of the invention is the improvement of the engine referred toabove in such a manner that it may be adapted to spatial requirements.More especially an overall extremely flat engine is intended which forexample is well suited for underfloor engines in automotive vehicles. Itis also intended to accommodate gear boxes and other units in a spacesaving manner within the outlines of the engine.

To solve this problem provision is made in accordance with the inventionfor the angle between two cylinders appertaining to the same crankshaftto be made smaller and/ or larger than 90.

According to the present invention a four cylinder twostroke opposingpiston internal combustion engine having four symmetrically arrangedcrankshafts, on which two pistons each act, the cylinders of which arearranged at an angle to one another, characterised by the feature thatthe angle between two cylinders appertaining to the same crankshaft maybe smaller and/or larger than 90.

Among other things this has the advantage that two opposite crankshaftsrotating in opposite directions are adapted to be connected, forexample, by only a few gear wheels. This method of construction also hasa better compensation of mass than the known square engine.

Furthermore the invention permits the construction of particularlycompact engine shapes adapted to the requirements of automotive vehiclesif the shorter of the two crankshaft connecting lines are arranged atright angles, so that the overall height of the engine is smaller thanits Width in that the angles between two cylinders operating on onecrankshaft are partly smaller, partly larger than 90.

It has also been proved that the constructional space required pervolumetric capacity due to the invention results in a minimum, i.e. theknown square engine re- 3,359,957 Patented Dec. 26, 1967 by thecylinders and crankshafts, for example becomes larger for receiving acharging blower.

The invention will be described further by way of example with referenceto the accompanying drawings, in which:

FIG. 1 is a rhornboidal engine;

FIG. 2 is an engine similar to that of FIG. 1 but having a bend in thecylinders in accordance to the invention,

FIG. 3 is a further embodiment of the engine according to FIG. 2, theangle between the cylinders in two crankshafts amounting to 180;

FIG- 4 is a further embodiment, in which the angles a have the sameoverall size.

FIG. 1 shows an engine in which the cylinders 5 and 8 appertaining to acrankshaft, e.g. the crankshaft 1 encloses an angle a;, which is smallerthan whilst the angle a between the cylinders 5 and 6 appertaining e.g.to crankshaft 2 is larger than 90. Owing to the symmetrical design arhornboidal shape is created. Three gear wheels 9, 10 and 11 connect thegear wheels 12, 13, 14 and 15 connected with the crankshafts. Thedirection of rotation of the gear wheels is indicated by arrows. Twoopposite shafts extend in an opposite direction of rotation relative tothe two other shafts, whereby a better compensation of mass of thereciprocating masses is obtained in comparison with the known squareengine.

Inlet and exhaust ports are designated E and A. In known manner thepiston, e.g. 16 controlling the exhaust port A, is in advance of forexample the piston 17 controlling the inlet E, whereby an asymmetricalcontrol diagram is obtained.

FIG. 2 shows an engine of similar arrangement of the crankshafts asillustrated in FIG. 1, in this case however the cylinders in the regionof the combustion chambers 21, 22, 23 and 24 are bent in accordance withthe invention and thus the bend in this embodiment faces outwardsrelative to the engine centre by forming an angle of bend b between thetwo cylinder parts 25 and 26. Thus, therefore the axes 27 and 28 of bothcylinder parts 25 and 26 intersect enclosing the angle b. This permitsthe combustion chambers to be better developed than hitherto and a largeutilizable interior engine space results with the same height/depth ofengine. Due to the angular combustion chambers the engine now hasnumerous corners the polygonal engine is also to be mentioned. Such anengine permits a particularly good cooling effect owing to the outwardlyarranged combustion chambers of the cylinders.

FIG. 3 shows a flat design polygonal engine in which the cylinder parts33 and 34 arranged in the center and e.g. acting on the shaft 31 enclosean angle of This creates in the center an H-shaped arrangement withhorizontally opposed cylinders, as known in connection with four strokeengines with single pistons. The invention herewith however permits tojoin V-shaped arrangement of cylinder parts, e.g. 35 and 36 to theH-shape, which act on the crankshaft 37. Without the angle of bend bthis is not possible. E and A designate again inlet and exhaust ports.In this case the exhaust ports are arranged on the outer side of theengine, whilst the inlet ports are located in the region of the shafts31 and 38 arranged at right angles one above the other. This permits inunderfloor engines for the exhaust pipes and silencers to be arrangedwithin the height of the engine.

FIGURE 4 illustrates a symmetrical polygon motor having a speciallylarge inside space of a diameter D, e.g. for accommodating a completedrive as used in vehicles where the space requirements are to be aminimum, such as caterpillar track Vehicles, tanks or the like. As arule, such motors are supercharged by an exhaust gas supercharger, amechanical supercharger thus not being necessary.

In that case all angles a and all angles b at the points ofdiscontinuity 45, 46, 47, 48 of the cylinders are greater than 90, themotor thus being mountable of similar components or elements. Thepistons cooperating with the inlet slots E act upon the crankshafts 42and 44, while the pistons associated with the outlet slots A cooperatewith the crankshafts 41 and 42. The crankshaft 41 meshes with thecentral gear 50 through the gears 51 and 52. The crankshaft 42 mesheswith the central gear 50 through the intermediate gear 55. Thecrankshaft 44 engages with the central gear 50 through the intermediategear 49, while the crankshaft 43 acts upon the central gear 50 throughthe intermediate gears 53 and 54.

What is claimed is:

1. A four cylinder two-stroke opposing piston internal combustion enginehaving four parallel arranged crankshafts arranged about a central axis,including a first two opposite crankshafts being closer together thanthe second two opposite crankshafts, two pistons acting on eachcrankshaft and the cylinders of which are arranged at an angle to oneanother, characterised by the fact that the angle between the twocylinders associated with the said first two opposite crankshafts beinggreater than and the angle between the two cylinders associated with thesaid second two opposite crankshafts being less than 90.

2. An engine as claimed in claim 1, in which the cylinders and thecrankshafts are arranged relative to one another in the form of arhombus.

3. An engine as claimed in claim 1, in which the cylinders, each ofwhich receiving two pistons, are bent in the region of their combustionchambers opposite their crankshaft ends, so that each cylinder isdivided in two cylinder parts each receiving a piston arranged at anangle relative to one another.

4. An engine as claimed in claim 1, in which a charging blower isarranged in the space enclosed by the cylinders and crankshaft.

5. An engine as claimed in claim 3, in which the said angle greater than90 amounts to References Cited UNITED STATES PATENTS 808,902 1/1906Crane 123-52 975,485 11/1910 Waltman 12353 1,814,802 7/1931 Herr 123522,085,270 6/1937 Pavlecka 12353 X FOREIGN PATENTS 864,939 1/ 1953Germany.

WENDELL E. BURNS, Primary Examiner.

1. A FOUR CYLINDER TWO-STROKE OPPOSING PISTON INTERNAL COMBUSTION ENGINEHAVING FOUR PARALLEL ARRANGED CRANKSHAFTS ARRANGED ABOUT A CENTRAL AXIS,INCLUDING A FIRST TWO OPPOSITE CRANKSHAFTS BEING CLOSER TOGETHER THANTHE SECOND TWO OPPOSITE CRANKSHAFTS, TWO PISTONS ACTING ON EACHCRANKSHAFT AND THE CYLINDERS OF WHICH ARE ARANGED AT AN ANGLE TO ONEANOTHER, CHARACTERISED BY THE FACT THAT THE ANGLE BETWEEN THE TWOCYLINDERS ASSOCIATED WITH THE SAID FIRST TWO OPPOSITE CRANKSHAFTS BEINGGREATER THAN 90* AND THE ANGLE BETWEEN THE TWO CYLINDERS ASSOCIATED WITHTHE SAID SECOND TWO OPPOSITE CRANKSHAFTS BEING LESS THAN 90*